I don't know what you infer on close reading but until dimensions point to the rare bird 9.3 Sauer, I have strong reservations as to the possibility, which has a very low probability. I think the red herring to be the "9.3 Sauer" term for now. I shoot several Meffert's with the same issue. It is a base issue and not a case mouth or neck. Many times Teschner-Collath examples have the 9.3X72R d stamp on the extractor. If anyone has ammo that will fit, M4 will be the most likely choice.

Kind Regards,

Raimey
rse